Index: scripts/repository/manage_repositories.php
===================================================================
--- scripts/repository/manage_repositories.php
+++ scripts/repository/manage_repositories.php
@@ -20,6 +20,7 @@
   new PhabricatorRepositoryManagementDiscoverWorkflow(),
   new PhabricatorRepositoryManagementListWorkflow(),
   new PhabricatorRepositoryManagementDeleteWorkflow(),
+  new PhabricatorRepositoryManagementMarkImportedWorkflow(),
   new PhutilHelpArgumentWorkflow(),
 );
 
Index: src/__phutil_library_map__.php
===================================================================
--- src/__phutil_library_map__.php
+++ src/__phutil_library_map__.php
@@ -1661,6 +1661,7 @@
     'PhabricatorRepositoryManagementDeleteWorkflow' => 'applications/repository/management/PhabricatorRepositoryManagementDeleteWorkflow.php',
     'PhabricatorRepositoryManagementDiscoverWorkflow' => 'applications/repository/management/PhabricatorRepositoryManagementDiscoverWorkflow.php',
     'PhabricatorRepositoryManagementListWorkflow' => 'applications/repository/management/PhabricatorRepositoryManagementListWorkflow.php',
+    'PhabricatorRepositoryManagementMarkImportedWorkflow' => 'applications/repository/management/PhabricatorRepositoryManagementMarkImportedWorkflow.php',
     'PhabricatorRepositoryManagementPullWorkflow' => 'applications/repository/management/PhabricatorRepositoryManagementPullWorkflow.php',
     'PhabricatorRepositoryManagementWorkflow' => 'applications/repository/management/PhabricatorRepositoryManagementWorkflow.php',
     'PhabricatorRepositoryMercurialCommitChangeParserWorker' => 'applications/repository/worker/commitchangeparser/PhabricatorRepositoryMercurialCommitChangeParserWorker.php',
@@ -4013,6 +4014,7 @@
     'PhabricatorRepositoryManagementDeleteWorkflow' => 'PhabricatorRepositoryManagementWorkflow',
     'PhabricatorRepositoryManagementDiscoverWorkflow' => 'PhabricatorRepositoryManagementWorkflow',
     'PhabricatorRepositoryManagementListWorkflow' => 'PhabricatorRepositoryManagementWorkflow',
+    'PhabricatorRepositoryManagementMarkImportedWorkflow' => 'PhabricatorRepositoryManagementWorkflow',
     'PhabricatorRepositoryManagementPullWorkflow' => 'PhabricatorRepositoryManagementWorkflow',
     'PhabricatorRepositoryManagementWorkflow' => 'PhutilArgumentWorkflow',
     'PhabricatorRepositoryMercurialCommitChangeParserWorker' => 'PhabricatorRepositoryCommitChangeParserWorker',
Index: src/applications/repository/management/PhabricatorRepositoryManagementMarkImportedWorkflow.php
===================================================================
--- /dev/null
+++ src/applications/repository/management/PhabricatorRepositoryManagementMarkImportedWorkflow.php
@@ -0,0 +1,67 @@
+<?php
+
+final class PhabricatorRepositoryManagementMarkImportedWorkflow
+  extends PhabricatorRepositoryManagementWorkflow {
+
+  public function didConstruct() {
+    $this
+      ->setName('mark-imported')
+      ->setExamples('**mark-imported** __repository__ ...')
+      ->setSynopsis('Mark __repository__, named by callsign, as imported.')
+      ->setArguments(
+        array(
+          array(
+            'name'        => 'mark-not-imported',
+            'help'        => 'Instead, mark repositories as NOT imported.',
+          ),
+          array(
+            'name'        => 'repos',
+            'wildcard'    => true,
+          ),
+        ));
+  }
+
+  public function execute(PhutilArgumentParser $args) {
+    $repos = $this->loadRepositories($args, 'repos');
+
+    if (!$repos) {
+      throw new PhutilArgumentUsageException(
+        "Specify one or more repositories to mark imported, by callsign.");
+    }
+
+    $new_importing_value = (bool)$args->getArg('mark-not-imported');
+
+    $console = PhutilConsole::getConsole();
+    foreach ($repos as $repo) {
+      $callsign = $repo->getCallsign();
+
+      if ($repo->isImporting() && $new_importing_value) {
+        $console->writeOut(
+          "%s\n",
+          pht("Repository '%s' is already importing.", $callsign));
+      } else if (!$repo->isImporting() && !$new_importing_value) {
+        $console->writeOut(
+          "%s\n",
+          pht("Repository '%s' is already imported.", $callsign));
+      } else {
+        if ($new_importing_value) {
+          $console->writeOut(
+            "%s\n",
+            pht("Marking repository '%s' as importing.", $callsign));
+        } else {
+          $console->writeOut(
+            "%s\n",
+            pht("Marking repository '%s' as imported.", $callsign));
+        }
+
+        $repo->setDetail('importing', $new_importing_value);
+        $repo->save();
+      }
+    }
+
+    $console->writeOut("Done.\n");
+
+    return 0;
+  }
+
+}